1. Field of the Invention
The present invention relates to a backlight assembly and a display device having the backlight assembly. More particularly, the present invention relates to a backlight assembly capable of reducing manufacturing costs thereof, and a display device having the backlight assembly.
2. Discussion of the Background
A liquid crystal display (LCD) device displays an image by using a liquid crystal material that has optical characteristics such as anisotropic refractivity as well as electrical characteristics such as an anisotropic dielectric constant. The LCD device has a number of advantageous characteristics compared to other display devices, such as cathode ray tube (CRT) devices and plasma display panel (PDP) devices. For example, LCD devices may be thinner and may be driven using a relatively low driving voltage, thereby consuming less power than other device types. As a result, LCD devices are commonly used for many different purposes.
However, LCD devices do not generate light to display an image. Therefore, an LCD device includes an LCD panel for displaying an image by using light transmittance of liquid crystals and a backlight assembly under the LCD panel to supply the LCD panel with light.
The LCD panel includes a first substrate having a plurality of thin-film transistors (TFTs) arranged to correspond to a plurality of unit pixels, a second substrate having a color filter arranged thereon, and a liquid crystal layer interposed between the first substrate and the second substrate. The color filter is arranged to correspond to the unit pixels, and includes red color filters, green color filters, and blue color filters.
The backlight assembly includes a light source that generates light to pass through the liquid crystal layer to display an image. The backlight assembly typically uses a cold cathode fluorescent lamp (CCFL), a flat fluorescent lamp (FFL), or a light-emitting diode (LED) as the light source.
The LED has become popular recently because the LED has a high luminance and consumes relatively less power than other types of light sources. When used as a light source for a backlight assembly, the LEDs may be disposed on a driving substrate and may be manufactured to have a chip shape. The LEDs include a red LED, a green LED, and a blue LED.
Recently, a local dimming method has been developed. In the local dimming method, some LEDs may emit light while other LEDs may not emit light during a frame. In order to drive the LEDs using the local dimming method, the number of the LEDs in the backlight assembly may be equal to the number of driving elements. Specifically, each LED may be connected to a driving element so that the driving elements individually activate each LED to control the light emission from the backlight assembly.
Therefore, a backlight assembly operated by the local dimming method has a number of driving elements equal to the number of LEDs. This increases the cost to manufacture a circuit for the backlight assembly operated by the local dimming method. Furthermore, the circuit for the backlight assembly operated by the local dimming method may be complicated.